Suppose best try easy things first.....Change CMOS battery, try with HDDs unplugged, reset BIOS to default, take out ssd and install one of the HDDs as boot drive ( create new partion and reinstall etc). If its an Asus board or something with an automatic overclocking utility disable it. The start up behaviour sounds like one of my overclocking misadventures but not the error msgs.
Presume you have checked all connectors? Its been a while but last time I looked another power connector has appeared on motherboards. I ran a machining skimping on one as the PSU was old and didn't have the right lead. Ran alright but.....